1. Field of the Invention
Aspects of the present invention relate to a touch screen panel and a fabrication method thereof, and more particularly, to a touch screen panel integrally formed on an upper substrate of a flat panel display and a fabrication method thereof.
2. Description of the Related Art
A touch screen panel is an input device that selects contents displayed on a screen such as an image display device, etc. using a person's hand or an object to input commands of a user.
To this end, a touch screen panel is provided on the front face of the image display device and converts positions directly contacting a person's hand or an object into electrical signals. Therefore, the command contents selected at the contact position are received as the input signals. As the touch screen panel can replace a separate input device that is operated by being connected with the image display device such as a keyboard or a mouse, the fields of use for touch screen panels are being expanded gradually.
For implementing the contact for a touch screen panel, a resistive type, a light sensing type, and a capacitive type, etc. have been known.
Among those, when the person's hand or the object contacts the touch screen panel in the capacitive type, the conductive sensing pattern senses the change in capacitance at other adjacent sensing patterns or ground electrodes, etc., thereby converting the contacting position into the electrical signals. In order to clearly determine the contacting position at the contacting surface, the sensing pattern is configured to include first sensing patterns (X patterns) formed to be connected along a first direction and second sensing patterns (Y patterns) formed to be connected along a second direction.
In the related art, the first and second sensing patterns each are disposed on different layers. In other words, as one example, the first sensing patterns are disposed on the lower layer, the second sensing patterns are disposed on the upper layer, and an insulating layer is interposed therebetween.
When each sensing pattern is formed on a different layer, a transparent conductive material (for example, ITO) is used as the sensing patterns have large surface resistance. Accordingly, in order to reduce the surface resistance, a wide connection part connects the sensing patterns disposed on the same layer. However, an overlapping area of each connection part disposed on the upper and lower layers becomes large and the capacity for parasitic capacitance accordingly becomes large, such that the sensitivity sensed by each sensing pattern deteriorates.
In order to overcome these disadvantages, in the related art the first and second sensing patterns can be formed on the same layer and can then be connected by forming separate connection patterns through contact holes formed through the insulating layer on the upper portions of the first or second sensing patterns. In these situations, the connection patterns are made of metal materials having low resistance.
As one example, the connection part of the first sensing patterns is made of the transparent conductive materials like the example disclosed above and the connection part of the second sensing patterns is made of low resistance metal materials and intersects with the connection part of the first sensing patterns.
In other words, the first sensing patterns and the second sensing patterns intersect with each other in the regions where the connection patterns are formed and the widths of the connection patterns are minimized, thereby making it possible to reduce the effect of the parasitic capacitance generated at the intersecting region.
However, even in this case, the connection part connecting the first sensing patterns is still made of the transparent conductive material having a high resistance value and reduces the overlapping area of the intersecting region. Also, since the connection pattern is disposed on the upper portion of the insulating layer, it is vulnerable to static electricity applied or occurring from the outside.